Helicopters have now become entrenched as an integral part of the weapons system carried by destroyers and frigates, in an anti-submarine search and strike capacity. Invariably landings and take-offs of these helicopters from the vessels must be made in moderate to severe turbulence and once on the deck, the helicopter must be quickly secured and stored for protection from the environment.
Two helicopters so used are the Westland Sea Lynx (t.m.) and Sea King (t.m.).
The Sea Lynx is a high performance helicopter which operates at a maximum All-Up-Weight of 10,000 pounds. It is powered by two Rolls Royce RS360 free turbine engines which are mounted side by side, on top of the fuselage behind the rotor. The Naval Version, developed and built to meet the requirements of both the Royal and French Navies for a manned-ship borne helicopter, incorporates special high energy absorption pneumatic tricycle landing gear and a pronged harpoon deck lock securing system. This deck lock securing system extends from the underbelly of the helicopter intermediate the dual-nose wheel and single main wheel units for engaging a special passive grid insert in the ship's deck. On landing, the deck lock system is hydraulically operated, rapidly engaging and locking on the passive ship mounted grid, and then tensioned to secure the helicopter with some 1,360 kg. (3,000 lbs.) of load tension between the helicopter and the deck.
Subsequently, the helicopter is moved to the hangar for maintenance and protection from direct damage from high seas and the corrosive effect of salt spray.
For maximum maneuverability and reliability, the nose wheel assembly of the Sea Lynx is hydraulically castered through 90.degree. and the main wheels may either be fixedly toed out at an angle of 27.degree. for deck landings or manually castered in line and locked fore and aft to allow the helicopter to be traversed into and out of, the ship's hangar. Sprag brakes (wheel locks) fitted to each wheel prevent rotation on landing or inadverent deck roll.
The Sea King, a 20,000 pound helicopter, on the other hand, includes a conventional undercarriage comprising a rear wheel free wheeling through 360.degree. and a pair of spaced dual wheel units on either side, and near the nose, of the helicopter. For recovery, employing the RAST System (Recovery Assist Secure and Traverse System) for helicopter recovery, the Sea King mounts externally on its underside an airborne messenger winch intermediate the rear wheel and pair of dual wheel units. The messenger winch holds a light duty cable with a messenger link and a lock assembly for the flydown cable. When the flydown cable from the self-centering and self-balancing sliding bell mouth is secured to the messenger winch, a constant tension is maintained in the cable until the helicopter is landed safely. Once the helicopter has landed an increased tension is applied automatically by the electric tension winch for securing the helicopter.
After landing, the Sea King Helicopter is likewise moved into the hangar.
It is therefore an object of this invention to provide a traversing system, components and sub-assemblies therefor, which permits the helicopter to be relatively easily secured to the traversing system and which permits the helicopter to be safely transported to and from the hangar with minimum manipulation.
It is a further object of the invention to provide such a traversing system, components and sub-assemblies therefor, which system acts as a direct connection between the helicopter and the ship permitting centering, aligning, and traversing the helicopter relative to the ship deck.
It is a further object of the invention to provide a traversing system, components and sub-assemblies therefor, which system employs minimal forces on the helicopter when used for traversing.
It is a further object of this invention to provide a traversing system, components and sub-assemblies therefor which system requires minimal modifications to the ship deck, helicopter, or haul-down systems employed.
It is also an object of this invention to provide a method for traversing a helicopter which requires minimal manipulation of the helicopter.
Further and other objects of the invention will be realized from the following summary and detailed description of the preferred embodiments thereof.